Last week I had a service call out to a home with an inoperable circuit. After some looking and talking heres what I found.

Split level home with a 125amp Square D panel in basement.The problem circuit ran from panel straight up to living room hit 6 plugs and some lighting and then dropped back downstairs to a pullchain.

The owner took the power out of the light ran it into a singlegang box for rec then up to a switch then back to the light. All his work appeard fine and no sign of damage anywhere, I looked very closely.

The breaker to this circuit is now dead,in tripped position will not reset. Each and every plug upstairs and through the switch's main feed on to the next plug have done a melt down, things just melted to each other causing shorts everywhere. The burn did not continue to inside the sleave of the romex but was contained in the box.

This was true of every wire upstairs both the hot and the nuetral. On the downstairs wire there was no sign of damage.

My best guess at this point is the homeowner goofed and wired his plug a dirrect short. He swears he didn't and has done things like this before. He seemed somewhat competant.

This was all on a 15amp square D homeline breaker. Homeowner said when he turned it on he could hear the buzzing for some time but didn't know what it was [Linked Image]

Heres the Q's. Why didn't it damage the wire downstairs where he would have made his mistake like it did the upstairs.

When he moved the wire maybe yanked it causing an already to tight staple to cut into the wire? Doubtfull. All wiring has been replaced. No sign of that and it was all looked at closely.

Also should a rep be notified this rings of FP breakers. Or should say UL be notified.

This is obviously a problem of a short and a major overcurrent through the wire compounded by a faulty breaker. Is it just a fluke?

Neil

[This message has been edited by Bomzin (edited 03-28-2004).]